Thermal energy storage by means of reversible heat pumping utilizing industrial waste heat

Abstract

An improved process for storing the off-peak electrical output of an electricity generating plant in the form of heat by using said off-peak electrical output to raise the temperature level of a quantity of stored low vapor pressure thermal energy retention material and recalling said stored heat during periods of peak power demand in the form of electrical power, or industrial process heat wherein the excess electrical power, running a compressor (i.e. heat pump), compresses low grade heat containing vapor thereby raising the temperature and said compressed high heat is transferred to a LVP thermal energy retention material, the improvement comprising using as a source of low grade heat the waste heat generated by industrial and/or municipal installation such as refineries, steel mills, incinerators, etc. The process utilizes hot low vapor pressure (LVP) thermal energy retention material and appropriate storage means and cold LVP thermal energy retention material and appropriate storage means, low level, low grade waste heat either alone or in combination with stored hot water, most preferably alone, heat exchanger means, heat pumping means, turbine means, electric motor means and generator means and/or industrial process heat utilization means.

What is claimed is: 
     
       1. In a process for storing the off-peak electrical output of an electricity generating plant in the form of heat in a low vapor pressure (LVP) organic heat retention material and recalling said heat from said LVP organic heat retention material during period of peak power demand by reconversion into electrical power or utilization as high quality process heat comprising the steps of: (a) using excess electrical power to run a compressor;   (b) compressing a low level heat containing vapor to raise the temperature of said heat containing vapor;   (c) contacting said high temperature heat containing vapor through heat exchanger means with an LVP material;   (d) storing said hot LVP material in isolation from the atmosphere at atmospheric pressure;   (e) during periods of peak power demand using said stored hot LVP material as fluid heat transfer medium in industrial applications; the improvement comprising using as the low level heat containing vapor in step (b) the waste heat containing vapor generated by industrial and/or municipal installations.     
     
     
       2. The improved process of claim 1 wherein the industrial application of step (e) is the generation of additional electricity. 
     
     
       3. The improved process of claim 1 wherein the industrial application of step (e) is an industrial process heat utilization means. 
     
     
       4. The improved process of claim 1 wherein the industrial application of step (e) comprises both industrial process heat utilization and additional electricity generation. 
     
     
       5. The improved process of claim 2 wherein additional electric power is generated during peak demand periods by the utilization of additional steam generated by means of the low level industrial waste heat available during said period. 
     
     
       6. The improved process of claim 1 wherein the industrial and/or municipal waste heat used as the source of low level heat is collected by means of a water loop wherein the water is heated so as to produce steam which is compressed by means of said compressor using excess electrical power whereby said steam is raised to a high temperature for contacting with the LVP material for storage. 
     
     
       7. The improved process of claim 6 wherein the hot water is used to heat a thermodynamic fluid which is compressed to a high temperature and used to heat a LVP material for storage. 
     
     
       8. The process of claim 6 wherein the hot water, produced in said water loop by contact with the waste heat source is used to heat a thermodynamic fluid which thermodynamic fluid is used to generate additional electric power.